Have 220 running from the main panel to a Hot Tub box with disconnect and a 110 outlet on the side of the house. Then hardwired to the hot tub. Installed in 2003 and have never had a problem until now.

Last month I heard a loud hum from the box and so turned it off. Tried to start it up again this week. At first it would trip immediately. Now it will run for up to an hour or so and then trip.

Checked inside the tub and can see no water or rodent issues. Have left the box open during a warm dry day to make sure that there wasn't a moisture issue inside of the box.

I am wondering if there is a way to test the GFCI in the hot tub box to see if perhaps it is faulty. Or any other ideas on what to check.

Thank you.

 

Really the only way to test it is to buy a new GFCI breaker and swap it out to see if the problem goes away.

Could be a small leak developing in the heater element. Check inside the disconnect box for any loose connections or heat damage also; humming can be caused by a loose connection.

 

You might just try replacing the GFCI. I don't know of any good way to test to see if it's tripping in error.